1. Field of the Disclosure
The invention relates to a hot melt adhesive, and a process for producing it.
2. Description of Related Art
Hot melt adhesives are adhesives that are applied in warm or hot condition to parts that are to be bonded together. The parts are then joined together. When cooled, the hot melt adhesive solidifies, and that binds the parts together. When heat is again applied, the hot melt adhesive is again softened, so that the bonding of the parts can be unbound, or their position with respect to one another can be changed. Steadily rising crude oil prices, while at the same time the availability of crude oil is falling, has led to increasing costs in the production of hot melt adhesives of that kind, because their main components are petroleum products.
From U.S. Pat. No. 5,434,201 a process for producing a hot melt adhesive is known, which contains a starch ester with a substitution level of 0.3 to 3.0, and a selected non-volatile organic plasticizer, whereby the starch ester is a water-based system, with at least 40 weight % moisture. Hot melt adhesives of that kind tend to experience phase separations when they solidify. A transparent matrix cannot be attained in that way.